Tension device for embroidering-machines.



M. SOHOENPELD. TENSION DEVICE FOR. EMBROIDEEING MACHINES.

APPLICATION FILED JUNE 13, 1910.

Patented Feb. 4

I X/ attoznc W COLUMBIA PLANOORAPH 60., WASHINGTON, D. C.

UNITED STATES PATENT OFFICE.

MORRIS SCHOENFELI), OF RORSCHAGI-I, SWITZERLAND.

TENSION DEVICE FOR EM BROIDERING-MACHINES.

To all whom it may concern:

Be it known that I, MORRIS SCHOENFELD, a citizen of the United States, and a resident of Rorschach, in the Canton of St. Gall, Switzerland, have invented certain new and useful Improvements in Tension Devices for Embroidering-Machines, of which the following is a specification.

In embroidering machines of the large type wherein the stitching mechanism is ar ranged in multiple along the machine there is provided a tension device, usually in the form of a roller with a rough frictional periphery which controls the let off of the threads and it is usually placed where itwill engage the threads between the supply spools or bobbins and the thread take up. The tension serves to control the let off of the threads so that the quick action of the take up will notunwind the thread faster than it is required in the stitching operation. Heretofore the tension device has been positively held at predetermined periods during the stitching operation and a single tension roller has been used for a number of the threads, usually a roller serving for all the threads of the stitching mechanism of a row. In the course of the stitching operation it often happens that for some reason the thread loop is delayed in responding to the action of the take up, such as when it is delayed in passing over a shuttle and since the tension is positively held and its time of movement fixed it often happens that the thread becomes broken. Since there are many threads in a machine, running into the hundreds, it is important that this breaking of the threads be avoided as far as possible. It is diflicult to arrange the driving of the tension so that its movement will be suitable for all threads to which the tension is common. In the present practice the tension roller is very rough on its surface so that there can be no slipping of the thread in relation to the tension roller, but this adds to the liability of thread breakage because of the positiveness of the tension feed.

The object of my present invention is to make it possible to retain all the advantages of a rough surface tension roller and at the same time reduce or eliminate the liability of breakage through the tension action. To do this I have produced a device wherein the tension drive may be positive and predetermined or in which the tension may be posi- Speeification of Letters Patent.

Application filed June 13, 1910.

i I i i l Patented Feb. 4, 1913.

Serial No. 566,498.

wherein there will be more or less elasticity in regard to the action of the tension on the threads. In the present device if the tension does not let off enough thread in any particular instance at all times, the thread, by reason of an undue tautness will cause an additional feeding from the supply bobbin. This is permitted by a movement of the thread engaging part of the tension mechanism with relation to the tension holding means and by employing springs, this relative movement is sufiiciently resisted to prevent the tension action from being nullified.

A further understanding of my invention may be had from the detailed description hereinafter.

In the drawings forming a part of this application, Figure 1 is an elevation of my invention wherein the threads operate individually in causing an additional feed when unduly taut, Fig. 2 is a similar view of another form of a similar character, Fig. 3 is a detailed View, and Fig. l is an elevation of the means for periodically holding the tension device.

In Fig. 1 I have shown my invention in a form wherein each thread acts independently of the others, so that if only one thread becomes unduly taut there is an extra feeding of that thread only and not all of the group. In this construction I have shown the shaft, which is held by means acting on the gear 4, built up of the studs 16 and the connecting sleeve 18, which latter carries the tension elements. I have arranged along this sleeve 18 a series of thread engaging tension elements which consist of the rings 20 having a roughened periphery with which the threads engage, but herein there is an individual ring for each of the several threads 21. The rings 20 are clamped between the metal plates 19, which preferably extend out in the form of flanges beyond the periphery of the rings, and these plates 19 are journaled loosely on the sleeve 18, whereby they may revolve about the same. Intermediate the several tension devices and separated therefrom and about the sleeve 18 I have provided spacing rings 25, which are fast upon the sleeve 18 and are revolved therewith. Between the several rings 25 and the plates 19 on each side of the tension elements I have arranged the collars 23wvhich abut against the faces of the plates 19 and a frictional engagement tively held during the take up action, but between these collars and the plates 19 is caused by the spiral springs 24, which abut between the rings 25 and the collars 23, and having their ends seated in the collars and the rings respectively. lVhen the holding device for the entire tension device is released the tension device as a whole is al lowed to revolve at a predetermined time at each stitch of the machine, the friction between. the collars 23 and the several plates 19 being sul'licient to cause the tension rings to revolve with the shaft. Should any thread become unduly taut at any time the undue tension of the thread on the engaging or tension rings 20 will cause the l attcr to overcome the frictional contact of the collars 23 with the plates 19 and the ring 20 will revolve an amount in addition to the movement produced by the revolution of the sleeve 18. That is, the tension ring will. revolve on the sleeve 18 and without atlecting the tension or feed of the other tension rings. In this form the threads are independent in their protective action, and should only one or several threads become unduly taut they do not produce an extra feed in all the other threads.

In Figs. 2 and 3 I have shown still another term of my invention in which each thread acts independently in its protective action, but in this form the amount of tautness necessary to produce the extra teed is adjusted by a single adjustment for the several tension elements. In this form there are short shafts 32, 33, as before, which carry the collars 39, 39, and between these latter is mounted a sleeve 3% which difi'ers from the sleeve 18 in that it has a longitudinal groove 35. The tension rings 37 over which the threads engage are clamped between the plates 36, which are so bowed that while they abut against each other they separate the several rings 37, and thus act as separators. The plates 36 are provided with projecting lugs 38 which extend into the longitudinal groove 35 ot the sleeve 34 and thus cause the plates to positively turn with the sleeve. At one end 01": the sleeve I have provided a spiral spring ll, which abuts against the collar 39 and a collar 10 and produces a frictional clamping of the several plates 36 against their respective tension rings 37. The collar 39 is adjustable along the shaft 32, for the purpose of increasing or decreasing the amount of tension or the spring 41 and thus the amount of friction between the parts. The shafts 32, 33, are controlled as the shafts in the previous constructions, by positive means. Should any of the threads become unduly taut they will overcome the friction between the plates 36 and the tension rings 37 and the latter will be revolved in addition to the revolution of the shaft and an additional amount of thread will be fed oft the bobbin to prevent a break in the thread. The

threads which are not unduly taut will not be affected by the increased feed of that one which is taut. By adjusting the tension of the spring 41 all the thread tension rings are adjusted at one time whereby the amount of undue tension necessary to overcome the friction of the tension rings with their plates, is adjusted. This may be necessary to adjust the device for threads of different strength. A thin thread would be more apt to break with a slight undue tension than a heavy thread.

Fig. 4 shows a well known device for pcriodically holdin the shaft 16. The shaft is the embroicering machine shat't. A cam secured on the shaft has a groove 13, in which travels a bowl 19, on an arm 11 of an angle lever. The other arm 10 of this lever is connected by a link 9, with a lever 7. One arm 6 of the latter serves as a pawl and is aranged to operate the gear l for the purpose of periodically holding the same, and its shaft 16, from revolving. The periodical rocking of the levers 10, 11, and 7, (3, causes the gear t to be periodically locked and unlocked.

In both of the forms herein shown the element of the tension device which directly engages with the thread may be rough enough and have a considerable friction upon the threads for the purpose of not only producing the necessary tension but also to cause the let off of the threads from their bobbins, so that the feed of the thread takes place at the proper times and resisted at the proper-time; and to prevent the take up from withdrawing the thread from the bobbins; and the threads are free to cause an additional feed off when unduly taut by causing a relative movement be tween the tension element and the holding device of the tension.

Various changes in form and construction may be made without departing from the spirit and scope of my invention. The location of the frictional or tensional releasing device may be changed, under the broad scope of my invention so long as an additional movement may be caused in the tension elements.

Having described my invention what 1 claim is;

l. A device of the class described embodying a revoluble tension device arranged to simultaneously act on a plurality of sewing threads, and adapted to be positively and periodically held from rotation, said tension device being adapted to be revolved as a whole by the combined action of the sewing threads when not positively held, and including revoluble means controlled individually by the several threads and adapted to be revolved upon an overtension of a thread or threads to let ott an amount of said thread or threads, in addition to the feed caused by the combined action of all the threads upon the tension device, and arranged to be revolved by the several threads when the tension device as a whole is held from rotation said tension device revolving only in one direction.

2. A device of the class described embodying a revoluble tension device arranged to simultaneously act on a plurality of sewing threads and adapted to be positively and periodically held from rotation, said tension device being adapted to be revolved by the combined action of the sewing threads when not positively held, and including revoluble elements individually controlled by the several threads, adapted to be revolved upon an overtension of a thread or threads to let off an amount of said thread or threads, in addition to the feed caused by the combined action of all the threads upon the tension device and arranged to be revolved by the several threads when the tension device as a whole is held from rotation and a spring for resisting the action of said individually operated elements said tension device revolving only in one direction.

3. A device of the class described, embodying a revoluble tension device, arranged to simultaneously act on a plurality of sewing threads, and adapted to be positively and periodically held from rotation, said tension device being adapted to be revolved by the combined action of the sow ing threads when not positively held and including elements individually revolved by the several threads, adapted to be revolved upon an overtension of a thread or threads to let off an amount of said thread or threads, in addition to the feed caused by the combined action of all the threads upon the tension device and arranged to be revolved by the several threads when the ten sion device as a whole is held from rotation, springs for individually resisting the action of said individually revolved elements and means for individuallyadjusting the resistance of said springs said tension device revo-lving only in one direction.

at. A device of the class described, embodying a revoluble tension device including a shaft on which the same is carried, said tension device being arranged to simultaneously act on a plurality of sewing threads, and said shaft being adapted to be positively and periodically held from rotation, said tension device being adapted to be revolved as a whole by the combined action of the sewing threads when said shaft is not positively held and including elements mounted to revolve with and in relation to, said shaft, said elements being individually controlled by the several threads and adapted to be revolved on the said shaft upon an overtension of a thread or threads to let off an amount of said thread or threads, in addition to the feed caused by the combined action of all the threads upon the said shaft, and arranged to be operated by the several threads when the said shaft is held from rotation said shaft and tension device revolving only in one direction.

Signed at St. Gall, in the Canton of St. Gall, Switzerland, this 2nd day of June 1910.

MORRIS SOHOENFELD.

WVitnesses CAESAR LOEB, FRIEDR- STEINER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, .D. C. 

